1. Field of the Invention
The present invention relates to an apparatus for controlling a head lamp for vehicle, the apparatus automatically controlling an illumination range of a head lamp mounted to a vehicle.
2. Description of Related Art
Various techniques for controlling, by use of image information, an illumination direction or an illumination range of a head lamp that is mounted to a vehicle such as an automobile for illuminating an environment ahead of the vehicle have been conventionally proposed. For example, Japanese Unexamined Patent Publication (JP-A) No. 2000-233683 describes a technique of controlling a head lamp to constantly have an optimum illumination direction by predicting an advancing direction of the vehicle with an image analysis, and controlling the head lamp to turn.
JP-A No. 2011-246023 describes a technique of controlling an illumination range of light toward the environment in front of a vehicle according to image information obtained by capturing an environment in front of the vehicle and vehicle-ahead information generated based upon road information that has possibility of becoming an obstacle upon detecting a vehicle ahead present in front of the vehicle. According to this technique, precision for detecting the vehicle ahead is enhanced, so that glare is difficult to be applied to the vehicle ahead.
However, the techniques described in the Publications described above do not assume the case in which the optical axis of the head lamp is shifted from a prescribed adjustment value. Therefore, according to these techniques, an appropriate illumination area of the head lamp cannot always be secured during when the vehicle travels.